Liquid crystal display device

ABSTRACT

A liquid crystal display device is disclosed. The device may include an array substrate including a first substrate, which is placed adjacent to a backlight, and a thin film transistor and a touch electrode, which are provided on the first substrate, and an opposite substrate including a second substrate, which faces the first substrate with a liquid crystal layer interposed therebetween, and a static electricity prevention layer, which is deposited on an outer surface of the second substrate. The static electricity prevention layer is formed of a host material containing at least one of In 2 O 3  and SnO 2  and a dopant material containing at least one of SiO 2 , ZrO 2 , HfO 2 , Nb 2 O 5 , and Ta 2 O 5  and has sheet resistance of about 10 6.5  Ω/sq to about 10 9  Ω/sq.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority benefit of Republic of KoreaPatent Application No. 10-2019-0143396 filed in Republic of Korea onNov. 11, 2019, which is hereby incorporated by reference in its entiretyfor all purposes as if fully set forth herein.

BACKGROUND Field

The present disclosure relates to a liquid crystal display (LCD) device,and in particular, to a touch LCD device.

Discussion of the Related Art

With the rapid transition to the information society, demands fordisplay devices of displaying images are increasing in various forms,and recently, various flat display devices, such as liquid crystaldisplay (LCD), plasma display panel (PDP), and organic light emittingdiode (OLED) devices, are being used in various fields.

The LCD device, one of the flat display devices, has technicaladvantages, such as small size, light weight, thin thickness, and lowpower consumption, and is widely used for many applications.

Recently, a touch sensing function is increasingly required for variousinformation display electronic devices, such as laptop computers orsmart phones, and thus, a touch sensor is applied to the LCD devices. Inparticular, an in-cell type touch LCD device, in which a liquid crystalpanel equipped with the touch sensor is provided, is being widely used.

In general, the conventional in-cell type touch LCD device is configuredto have an inverted panel structure. In the inverted panel structure, anarray substrate is disposed adjacent to a display surface, to which atouch event is input, whereas an opposite substrate, which is oppositeto the array substrate, is disposed at a lower portion of the LCDdevice. A transparent conductive layer is formed on an outer surface ofthe opposite substrate so as to prevent static electricity in anauto-probe test step, and a polarizing plate with a static electricityprevention layer is attached to an outer surface of the array substratefor touch sensing and static electricity prevention. Furthermore, in theinverted panel structure, an inorganic insulating layer is additionallyformed so as to prevent a user from recognizing reflection by a gatemetal.

For the touch LCD device of the conventional inverted panel structure,it is necessary to form the additional inorganic insulating layer and toprepare a highly expensive polarizing plate with a static electricityprevention function and an additional apparatus for inverting the panel.Accordingly, there are problems, such as low productivity and highfabrication cost, in the conventional touch LCD device.

SUMMARY

Accordingly, the present disclosure is directed to an LCD device thatsubstantially obviates one or more of the problems due to limitationsand disadvantages of the related art.

An object of the present disclosure is to provide a touch LCD devicethat can effectively realize an increase of productivity and a reductionin fabrication cost.

Additional features and advantages of the disclosure will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by practice of the disclosure. Theadvantages of the disclosure will be realized and attained by thestructure particularly pointed out in the written description and claimsas well as the appended drawings.

To achieve these and other advantages, and in accordance with thepurpose of the present disclosure, as embodied and broadly describedherein, a liquid crystal display device includes an array substrateincluding a first substrate, which is placed adjacent to a backlight,and a thin film transistor and a touch electrode which are provided onthe first substrate, and an opposite substrate including a secondsubstrate, which faces the first substrate with a liquid crystal layerinterposed therebetween, and a static electricity prevention layer whichis deposited on an outer surface of the second substrate, wherein thestatic electricity prevention layer is formed of a host materialcontaining at least one of In₂O₃ and SnO₂ and a dopant materialcontaining at least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅ and hassheet resistance of about 10^(6.5) Ω/sq to about 10⁹ Ω/sq.

In another aspect, a method of fabricating a liquid crystal displaydevice includes fabricating an array substrate including a firstsubstrate, which is placed adjacent to a backlight, and a thin filmtransistor and a touch electrode which are provided on the firstsubstrate, and fabricating an opposite substrate including a secondsubstrate, which faces the first substrate with a liquid crystal layerinterposed therebetween, and a static electricity prevention layer whichis deposited on an outer surface of the second substrate, wherein thestatic electricity prevention layer is formed of a host materialcontaining at least one of In₂O₃ and SnO₂ and a dopant materialcontaining at least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅ and hassheet resistance of about 10^(6.5) Ω/sq to about 10⁹ Ω/sq.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the description serve to explain the principles of thedisclosure. In the drawings:

FIG. 1 is a plan view schematically illustrating a touch LCD deviceaccording to an embodiment of the present disclosure.

FIG. 2 is a plan view schematically illustrating a liquid crystal panelaccording to an embodiment of the present disclosure.

FIG. 3 is a plan view illustrating a portion of a touch block of anarray substrate of an LCD device according to an embodiment of thepresent disclosure.

FIG. 4 is a cross-sectional view illustrating a portion of a touch blockof an LCD device according to an embodiment of the present disclosure.

FIGS. 5 to 7 are cross-sectional views schematically illustrating aprocess of fabricating an opposite substrate of a touch LCD deviceaccording to an embodiment of the present disclosure.

FIG. 8 is a graph showing a variation of sheet resistance over time in acomparative experiment.

FIGS. 9 and 10 are graphs showing variations of sheet resistance overtime in an experiment 1 of the present disclosure.

FIG. 11 is a graph showing results of transmittance versus wavelength,obtained in the experiment 1 of the present disclosure.

FIG. 12 is a graph showing results of sheet resistance obtained from achemical resistance test, in the experiment 1 of the present disclosure.

FIGS. 13 to 15 are graphs showing variations of sheet resistance overtime in an experiment 2 of the present disclosure.

FIGS. 16A-16F are diagrams showing sheet resistances obtained fromthermal treatment stability and chemical resistance tests, in anexperiment 3 of the present disclosure.

FIGS. 17A-17F are diagrams showing sheet resistances obtained from 6090reliability and chemical resistance tests, in the experiment 3 of thepresent disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. The same or like referencenumbers may be used throughout the drawings to refer to the same or likeparts.

A touch LCD device according to the present disclosure may have anin-cell structure, in which a touch sensor is provided in a liquidcrystal panel, and may be operated in all kinds of capacitive touchsensing manners (e.g., the self-capacitive and mutual-capacitive sensingmanners).

In the embodiments to be described below, a touch LCD device operated inthe self-capacitive method will be described by way of example, forconcise description.

FIG. 1 is a plan view schematically illustrating a touch LCD deviceaccording to an embodiment of the present disclosure, and FIG. 2 is aplan view schematically illustrating a liquid crystal panel according toan embodiment of the present disclosure.

Referring to FIGS. 1 and 2, a touch LCD device 10 according to thepresent embodiment may include a liquid crystal panel 100, which isconfigured to display an image and is provided with a touch device, anda cover window CW, which is attached to a front surface of the liquidcrystal panel 100 serving as an image display surface, in short adisplay surface.

Although not illustrated in detail, a back-light unit may be disposedbelow the liquid crystal panel 100 to provide light to the liquidcrystal panel 100.

An edge-type back-light unit, in which a light source (e.g., a lightemitting diode (LED)) is disposed adjacent to the liquid crystal panel100 in a lateral direction, or a direct-type back-light unit, in whichthe light source is disposed below the liquid crystal panel 100, may beused as the back-light unit.

In the present embodiment, the liquid crystal panel 100 may have anin-cell structure, in which a touch electrode 151, one ofself-capacitive touch devices, is provided in the panel. For example,the touch electrode 151 may be disposed in one of two substrates AS andOS of the liquid crystal panel 100.

In the liquid crystal panel 100 of the in-cell structure, the touchelectrode 151 having a touch sensing function may be applied with acommon voltage during an image display period of the liquid crystalpanel 100, thereby serving as a common electrode 151. The touchelectrode 151 may be applied with a touch driving signal during a touchsensing period between the image display periods, and in this case, thetouch electrode 151 may be used as a touch sensing electrode.

The liquid crystal panel 100 of the in-cell structure may include anarray substrate AS, which is provided adjacent to the back-light unit toserve as a lower substrate, an opposite substrate OS, which is providedadjacent to the image display surface to serve as an upper substrateopposite to the array substrate AS, and a liquid crystal layer, which isprovided between the array substrate AS and the opposite substrate OS.

In an embodiment, the liquid crystal panel 100 may be configured to havethe array substrate AS, in which a pixel electrode and the touchelectrode 151 (i.e., the common electrode 151) are formed as electrodesthat are used to produce an electric field for driving the liquidcrystal layer.

For example, a liquid crystal panel, which is operated in an in-planeswitching (IPS) or advanced high performance IPS (AH-IPS) manner, may beused as the liquid crystal panel 100. In the present embodiment, aliquid crystal panel, which is operated in the AH-IPS mode to produce afringe field, will be referred to as an example of the liquid crystalpanel 100, for concise description.

The liquid crystal panel 100 may include a display region AA, which isused to display an image, and a non-display region NA, which is providedadjacent to the display region AA. The display region AA may include aplurality of pixel regions, which are disposed in a row direction and acolumn direction to form a matrix-shaped arrangement.

A plurality of touch blocks TB may be disposed in the liquid crystalpanel 100 and, in an embodiment, the touch blocks TB may be disposed inthe row direction and the column direction to form a matrix-shapedarrangement. Each of the touch blocks TB may be constituted by aplurality of pixel regions as a unit group, which are adjacent to eachother in the row direction and the column direction.

In the array substrate AS of the liquid crystal panel 100, the touchelectrode 151 (i.e., the common electrode 151) may be patterned andformed in each of the touch blocks TB by a patterning process.

The common electrodes 151, which are respectively provided in adjacentones of the touch blocks TB, may be physically spaced apart from eachother, and thus, the common electrode 151 in each touch block TB may beprovided as an isolated pattern.

Accordingly, the common electrodes 151, which are provided in adjacentones of the touch blocks TB, may be electrically disconnected from eachother, and thus, the touch block TB may be operated in a separate orindependent manner.

Touch lines SL extending in a specific direction may be formed in thearray substrate AS of the liquid crystal panel 100 and may be connectedto the touch blocks TB, respectively. For example, the touch line SL maybe formed parallel to the column direction or a vertical direction,which is an extension direction of a data line.

Each of the touch lines SL may be connected to the common electrode 151in corresponding one of the touch blocks TB through a contact hole TCH,which is formed in the corresponding touch block TB, and may be used todeliver a driving signal to the common electrode 151.

During the image display period (e.g., each frame), a common voltage maybe applied to the common electrode 151 through the touch line SL. Thus,in each pixel region in the touch block TB, an electric field may beproduced between the pixel electrode and the common electrode 151, andsuch an electric field may be controlled to drive the liquid crystallayer and thereby to display an image.

During the touch sensing period between the image display periods (e.g.,a blank period between adjacent frames), a touch driving signal may beapplied to the common electrode 151 (i.e., the touch electrode 151)through the touch line SL.

In addition, a sensing signal may be detected by the common electrode151 and may be applied to the touch line SL, and in this case, thesensing signal is produced to contain information on a variation inelectrostatic capacitance of each touch block TB caused by a touchevent. The sensing signal may be used to determine whether there is atouch event provided from a user.

As described above, the common electrode 151 in the touch block TB maybe used as not only an electrode for producing an electric field butalso the touch electrode 151 for sensing a touch event, and thus, it maybe possible to realize the liquid crystal panel 100 of the in-cellstructure and to reduce a thickness of the liquid crystal panel 100.

In an embodiment, the opposite substrate OS facing the array substrateAS may be provided to have a size smaller than the array substrate AS.For example, the opposite substrate OS may be disposed to expose aportion of an edge region of the array substrate AS. In detail, theopposite substrate OS may not cover a lower edge region of the arraysubstrate AS, in which a panel driving circuit 300 is disposed, andwhich is overlapped with the non-display region NA.

The panel driving circuit 300 may be fabricated in the form of, forexample, an integrated circuit (IC) and then may be mounted on thenon-display region NA of the array substrate AS in a chip-on-glass (COG)manner.

The panel driving circuit 300 may be configured to produce variousdriving signals, which are required to operate the liquid crystal panel100, and to provide such driving signals to the liquid crystal panel100. That is, the operations of the liquid crystal panel 100 may becontrolled by the driving signals provided from the panel drivingcircuit 300.

For example, the panel driving circuit 300 may output a gate signal to agate line and may output a data signal to a data line. Furthermore, thepanel driving circuit 300 may output a common voltage or a touch drivingsignal to the touch line SL. The panel driving circuit 300 may receive asensing signal, which is produced in the common electrode 151, throughthe touch line SL.

The panel driving circuit 300 may include a data driving circuit, a gatedriving circuit, and a touch sensing circuit, which are configured todrive the data line, the gate line, and the touch line, respectively. Inan embodiment, the data driving circuit, the gate driving circuit, andthe touch sensing circuit may be provided as separate integratedcircuits. In another embodiment, an integrated circuit, in which atleast two of the circuits are integrated, may be used. In the presentembodiment, a single integrated circuit, in which all of the datadriving circuit, the gate driving circuit, and the touch sensing circuitare integrated, may be used as the panel driving circuit 300.

As another example, the panel driving circuit 300, which is provided inthe form of an IC, may be mounted on a flexible circuit film and may beconnected to the liquid crystal panel 100 through the flexible circuitfilm.

Hereinafter, a structure of an LCD device 10 according to the presentembodiment will be described in more detail with reference to FIGS. 3and 4.

FIG. 3 is a plan view illustrating a portion of a touch block of anarray substrate of an LCD device according to an embodiment of thepresent disclosure. FIG. 4 is a cross-sectional view illustrating aportion of a touch block of an LCD device according to an embodiment ofthe present disclosure.

Referring to FIGS. 3 and 4, an LCD device 10 according to an embodimentof the present disclosure may include a liquid crystal panel 100, afirst polarizing plate 201 attached to a bottom surface of the liquidcrystal panel 100, a second polarizing plate 202 attached to a topsurface of the liquid crystal panel 100, and a cover window CW attachedto a top surface of the second polarizing plate 202. Here, the bottomand top surfaces of the liquid crystal panel 100 may be outer surfacesof the liquid crystal panel 100, which are opposite to each other andare respectively located adjacent to the back-light unit and the imagedisplay surface.

A thin film transistor T and the touch electrode 151, which is used asthe common electrode, may be formed in the array substrate AS of theliquid crystal panel 100. In addition, a color filter pattern 130 may beformed in the array substrate AS.

A gate line GL may be formed on a top or inner surface of a firstsubstrate 101 to extend in a first direction (e.g., the row direction).A gate electrode 111 may be formed and may be connected to the gate lineGL. The gate line GL and the gate electrode 111 may be formed of thesame metallic material, in the same process. The gate line GL and thegate electrode 111 may be formed to have a single- or multi-layeredstructure, which contains at least one of, for example, aluminum (Al),aluminum alloys (e.g., AlNd), copper (Cu), molybdenum (Mo), molybdenumalloys (e.g., MoTi), and chromium (Cr).

A gate insulating layer 113, which is an insulating layer, may be formedon the gate line GL and the gate electrode 111. The gate insulatinglayer 113 may be formed of or include at least one of inorganicinsulating materials (e.g., silicon oxide and silicon nitride).

On the gate insulating layer 113, a semiconductor layer 115 may beformed corresponding to the gate electrode 111. The semiconductor layer115 may be formed of or include at least one of, for example, amorphoussilicon and oxide semiconductor materials.

A source electrode 121 and a drain electrode 123, which are spaced apartfrom each other, may be formed on the semiconductor layer 115. A dataline DL may be formed on the gate insulating layer 113 to extend in asecond direction (e.g., the column direction) crossing the firstdirection. The source electrode 121, the drain electrode 123, and thedata line DL may be formed of the same metallic material, in the sameprocess. The data line DL, the source electrode 121, and the drainelectrode 123 may be formed to have a single- or multi-layeredstructure, which contains at least one of, for example, aluminum (Al),aluminum alloys (e.g., AlNd), copper (Cu), molybdenum (Mo), molybdenumalloys (e.g., MoTi), and chromium (Cr).

A plurality of pixel regions P may be defined in a matrix shape by thegate line GL and the data line DL crossing each other.

The gate electrode 111, the semiconductor layer 115, the sourceelectrode 121, and the drain electrode 123 may constitute the thin filmtransistor T in each pixel region P.

In the present embodiment, a transistor of an inverted-staggered or abottom-gate structure is illustrated as an example of the thin filmtransistor T. However, in an embodiment, a thin film transistor of acoplanar or top-gate structure may be provided as the thin filmtransistor T, and in this case, the semiconductor layer may be formed ofor include at least one of polysilicon or oxide semiconductor materials.

A first protection layer 125, which is an insulating layer, may beformed on the entire region of the first substrate 101 to cover the thinfilm transistor T. The first protection layer 125 may be formed of orinclude at least one of inorganic or organic insulating materials. Here,the inorganic insulating material may include, for example, siliconoxide, silicon nitride, or the like, and the organic insulating materialmay include photo acryl, benzocyclobutene or the like.

On the first protection layer 125, the color filter pattern 130 may beformed corresponding to each pixel region P.

In the liquid crystal panel 100, the pixel regions P of red (R), green(G), and blue (B) colors may be alternately disposed in a specificdirection (e.g., the row direction), as exemplarily shown in FIG. 4, andcolor filter patterns 130 of red (R), green (G), and blue (B) colors maybe patterned and formed in the pixel regions P of red (R), green (G),and blue (B) colors to display their own colors.

In the present embodiment, the LCD device 10 has been described to havea color filter on thin film transistor (COT) structure, in which thecolor filter pattern 130 is formed on the thin film transistor T of thearray substrate AS. As another example, the LCD device 10 may beconfigured to have a structure, in which the color filter pattern 130 isprovided as a part of the opposite substrate OS.

A second protection layer 135, which is an insulating layer, may beformed on the entire region of the first substrate 101 to cover thecolor filter pattern 130. The second protection layer 135 may be formedof or include at least one of inorganic or organic insulating materials.

The touch line SL may be formed on the second protection layer 135. Inthe touch block TB, the touch line SL may be extended in an extensiondirection of the data line DL and may be overlapped with the data lineDL. In the case where the touch line SL is disposed to overlap with thedata line DL, which is one of non-display elements, it may be possibleto maximally increasing a width of the touch line SL, without areduction of an aperture ratio by the presence of the touch line SL, andthereby to allow the touch line SL to have a lowered resistance.

A third protection layer 137, which is an insulating layer, may beformed on the entire region of the first substrate 101 to cover thetouch line SL. The third protection layer 137 may be formed of orinclude at least one of inorganic or organic insulating materials.

A pixel electrode 140 may be formed on the third protection layer 137and in each pixel region P. Here, the pixel electrode 140 may be formedto have a substantially plate shape in each pixel region P. The pixelelectrode 140 may be connected to the drain electrode 123 of the thinfilm transistor T in a corresponding one of the pixel regions P. Forexample, the pixel electrode 140 may be in contact with and connected tothe drain electrode 123 through a drain contact hole CHd, which isformed to penetrate the first, second, and third protection layers 125,135, and 137.

A fourth protection layer 143, which is an insulating layer, may beformed on the pixel electrode 140. The fourth protection layer 143 maybe formed of or include at least one of inorganic or organic insulatingmaterials.

The touch electrode 151 (i.e., the common electrode 151) may be formedon the fourth protection layer 143 and in each touch block TB. Thecommon electrode 151, in conjunction with the pixel electrode 140, mayproduce a fringe field that is used to change an alignment direction ofliquid crystal molecules.

To produce the fringe field, the common electrode 151 may include aplurality of bar-shaped electrode patterns 152, which face the pixelelectrode 140 corresponding to each pixel region P, and an opening maybe formed between the electrode patterns 152.

Regarding the disposition or arrangement structure of the commonelectrode 151 and the pixel electrode 140, in another embodiment, thecommon electrode 151 may be provided in a plate shape substantially ineach touch block TB, whereas the pixel electrode 140, which is composedof a plurality of electrode patterns, may be provided on the commonelectrode 151 with an insulating layer interposed therebetween.

In other embodiment, each of the common and pixel electrodes 151 and 140may be formed to have an electrode pattern, and they may be disposed onthe same layer or may be disposed with an insulating layer interposedtherebetween.

A first alignment layer 191 may be formed on the top surface of thearray substrate AS to determine an initial alignment of liquid crystalmolecules. In other words, the first alignment layer 191 may be formedon the common electrode 151. The first alignment layer 191 may be formedof or include, for example, polyimide.

In an embodiment, the first polarizing plate 201 may be attached to thebottom or outer surface of the array substrate AS. Here, the firstpolarizing plate 201 may be directly attached to the bottom surface ofthe first substrate 101 through an adhesive member.

For example, a typical polarizing plate may be used as the firstpolarizing plate 201, and in this case, the first polarizing plate 201may include a polarizing layer and protection layers, which are providedon opposite surfaces (i.e., bottom and top surfaces) of the polarizinglayer, but may not need an additional static electricity preventionlayer having a static electricity prevention function. The firstpolarizing plate 201 may have a sheet resistance of about 10¹² Ω/sq orhigher, and in this case, the first polarizing plate 201 cannot be usedas a static electricity prevention element, because the first polarizingplate 201 has substantially an insulating property.

The opposite substrate OS may be combined with the array substrate ASand may face the array substrate AS, with a liquid crystal layer 105interposed therebetween. The opposite substrate OS may be disposedadjacent to the display surface of the liquid crystal panel 100, whichis used to display an image, and to which a touch event is input.

The opposite substrate OS may include a column spacer 160, which isprovided on a bottom or inner surface of a second substrate 102 and isused to maintain a cell gap or a thickness of the liquid crystal layer105. The column spacer 160 may be disposed corresponding to non-displayelements (e.g., the thin film transistor T, the data line DL, the gateline GL, and so forth) in the array substrate AS.

The column spacer 160 may be formed through a mask process and, forexample, may be formed by performing several processes includingdeposition, exposure, developing, etching, and strip processes. Athermal treatment process may be performed on the column spacer 160formed by the mask process.

The column spacer 160 may be formed to include a black pigment, and inthis case, the column spacer 160 may have a light-blocking functionpreventing or suppressing leakage light from entering a neighboringpixel region, like a black matrix.

A second alignment layer 192 may be formed on the inner surface of thesecond substrate 102 provided with the column spacer 160. The secondalignment layer 192 may be formed of or include, for example, polyimide.

The second alignment layer 192 may be formed through a process ofcoating an alignment material, and thereafter, a thermal treatmentprocess may be performed. Similarly, the first alignment layer 191 maybe formed through a coating process, and then a thermal treatmentprocess may be performed.

A static electricity prevention layer 220 may be formed on a top orouter surface of the second substrate 102.

The static electricity prevention layer 220 may be used to dischargestatic electricity, which is produced in a fabrication process of theLCD device 10 (for example, including a test process), to the outside.Since the static electricity prevention layer 220 is placed adjacent tothe display surface of the LCD device 10, it is necessary to configurethe static electricity prevention layer 220 so as to suppressinterference with an electrostatic capacitance between a user's fingerand the touch electrode 151, which is produced when a touch event isinput through the display surface of the LCD device 10.

To achieve the static electricity prevention without the interferencewith the touch-induced capacitance, the static electricity preventionlayer 220 in the present embodiment may have a sheet resistancepreferably ranging from about 10^(6.5) Ω/sq to about 10⁹ Ω/sq.

With regard to a proper range of the sheet resistance, if the sheetresistance is less than 10^(6.5) Ω/sq, the static electricity preventionlayer 220 may act as a conductor causing interference with electrostaticcapacitance by a touch event, and this may lead to a difficulty inrecognizing the touch event. By contrast, if the sheet resistance isgreater than 10⁹ Ω/sq, the static electricity prevention layer 220 mayact as an insulator hindering static electricity from being exhausted tothe outside, and thus, defects caused by the static electricity mayoccur.

Accordingly, the static electricity prevention layer 220 may bepreferably configured to serve as a dielectric material preventing theinterference issue with touch-induced capacitance when there is a touchevent and to serve as a conductor preventing the static electricityissue when there is a static electricity issue. For example, the staticelectricity prevention layer 220 is configured to have sheet resistanceof about 10^(6.5) Ω/sq to about 10⁹ Ω/sq.

In addition, preferably, the static electricity prevention layer 220 mayhave transmittance that is sufficiently high not to cause anysubstantial change in brightness of an image, because the staticelectricity prevention layer 220 in the present embodiment is placedadjacent to the display surface. For example, the static electricityprevention layer 220 is configured to have transmittance of about 97% orhigher.

To allow the static electricity prevention layer 220, which is formed onthe opposite substrate OS, to have the reliable sheet resistance andtransmittance properties, the static electricity prevention layer 220 inthe present embodiment may be preferably formed of a host materialincluding at least one of In₂O₃ and SnO₂ and a dopant material includingat least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅.

The static electricity prevention layer 220 formed of the material mayhave a thickness of about 100 Å to about 300 Å.

In the static electricity prevention layer 220, a content of the dopantmaterial may be in a range of about 9 wt % to 15 wt %, and a content ofthe host material, which is given by subtracting the content of thedopant material from the total content, may be in a range of about 85 wt% to 91 wt %.

In the case where one of In₂O₃ and SnO₂ is used as the host material,the content of the dopant material may be in a range of about 12 wt % toabout 15 wt %, and the content of the host material may be in a range ofabout 85 wt % to about 88 wt %.

In the case where a mixture of In₂O₃ and SnO₂ is used as the hostmaterial, the content of the dopant material may be in a range of about9 wt % to about 11 wt %, and the content of the host material may be ina range of about 89 wt % to about 91 wt %.

As described above, the content of the dopant material may varydepending on the composition of the host material, and consequently, thecontent of the host material may be changed.

Meanwhile, as the content of the dopant material increases, the sheetresistance of the static electricity prevention layer 220 increases.Even in such cases, by adjusting the content of the dopant material, thesheet resistance of the static electricity prevention layer 220 may becontrolled to be within a range required for the LCD device 10.

Furthermore, by adjusting an oxygen partial pressure in a processchamber during a process of depositing the static electricity preventionlayer 220 on the second substrate 102, the sheet resistance of thestatic electricity prevention layer 220 can be controlled to be withinthe range required for the LCD device 10, and this will be described inmore detail below.

The second polarizing plate 202 may be attached to a top or outersurface of the opposite substrate OS provided with the staticelectricity prevention layer 220. Here, the second polarizing plate 202may be directly attached to the top surface of the static electricityprevention layer 220 through an adhesive member.

For example, similar to the first polarizing plate 201, a typicalpolarizing plate may be used as the second polarizing plate 202, and inthis case, the second polarizing plate 202 may include a polarizinglayer and protection layers, which are provided on opposite surfaces(i.e., bottom and top surfaces) of the polarizing layer, but may notneed an additional static electricity prevention layer having a staticelectricity prevention function. The second polarizing plate 202 mayhave a sheet resistance of about 10¹² Ω/sq or higher, and in this case,the second polarizing plate 202 cannot be used as a static electricityprevention element, because the second polarizing plate 202 hassubstantially an insulating property.

The cover window CW may be attached to a top or outer surface of thesecond polarizing plate 202, which is provided on the top or displaysurface of the liquid crystal panel 100, to which the first and secondpolarizing plates 201 and 202 are attached. Here, the cover window CWmay be directly attached to the top surface of the second polarizingplate 202 through an adhesive member.

As described above, in the touch LCD device 10 of the in-cell structureaccording to the present embodiment, the static electricity preventionlayer 220, which is formed of a host material including at least one ofIn₂O₃ and SnO₂ and a dopant material including at least one of SiO₂,ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅, may be formed on the outer surface of theopposite substrate OS. In the case where the static electricityprevention layer 220 is formed of the materials, it may be possible toeffectively secure a sheet resistance of about 10^(6.5) Ω/sq to about10⁹ Ω/sq, which is advantageous to prevent the issues of staticelectricity and interference with touch-induced capacitance, and toeffectively secure the transmittance of about 97% or higher, which isadvantageous to maintain the image brightness to a desired level.

Thus, the opposite substrate OS can be disposed adjacent to the displaysurface or the top surface of the liquid crystal panel 100, and thus,the in-cell touch LCD device can be configured to have the non-invertedpanel structure.

Thus, it may be possible to effectively overcome the technical problems,which occur in the conventional inverted panel structure. For example,it is unnecessary to form an additional inorganic insulating layer forreducing the recognition of reflection by the gate metal in the invertedpanel structure. Furthermore, it is unnecessary to provide an expensivepolarizing plate having a static electricity prevention function nearthe display surface, and a typical polarizing plate can becost-effectively used in the inverted panel structure. In addition, anadditional apparatus for inverting the panel is not required.

Furthermore, the static electricity prevention layer 220 may be formedusing the existing sputtering system, which is used to form atransparent conductive layer on the outer surface of the oppositesubstrate, as it is, and thus, there is no additional cost to prepare anew system.

Thus, according to the present embodiment, it may be possible to improveproductivity and to reduce fabrication cost.

Hereinafter, a method of fabricating a touch LCD device, which is of thein-cell structure and has the afore-described features, will bedescribed in more detail with reference to FIGS. 5 to 7.

FIGS. 5 to 7 are cross-sectional views schematically illustrating aprocess of fabricating an opposite substrate of a touch LCD deviceaccording to an embodiment of the present disclosure.

Referring to FIG. 5, the second substrate 102 of the opposite substrateOS may be placed in a sputtering deposition chamber 400, and asputtering process may be performed on an outer surface of the secondsubstrate 102 to form the static electricity prevention layer 220 on atleast a part or the entire outer surface of the second substrate 102.

In the sputtering process, a target, which is a deposition source, maybe composed of a host material and a dopant material, which areexploited to form the static electricity prevention layer 220. In anembodiment, the host material may include at least one of In₂O₃ andSnO₂, and the dopant material may include at least one of SiO₂, ZrO₂,HfO₂, Nb₂O₅, and Ta₂O₅.

Since the target is used for the sputtering process, the host materialand the dopant material may be deposited to form the static electricityprevention layer 220, and in an embodiment, the static electricityprevention layer 220 may be formed to have a thickness of for example,about 100 Å-300 Å.

The static electricity prevention layer 220 may stably maintain thesheet resistance range of about 10^(6.5) Ω/sq to about 10⁹ Ω/sq, whichis required for the LCD device 10, even after a subsequent process onthe opposite substrate OS. Accordingly, it may be possible to secure thestatic electricity prevent property and to prevent the interference withelectrostatic capacitance caused by a touch event. Furthermore, for thestatic electricity prevention layer 220 having the afore-describedfeatures, it may be possible to stably maintain the transmittance to avalue of about 97% or higher and thereby to secure a desired imagebrightness of the touch LCD device.

To stably secure the sheet resistance property in the static electricityprevention layer 220, a content of the dopant material may be in a rangeof about 9 wt % to about 15 wt %, and a content of the host material maybe in a range of about 85 wt % to about 91 wt %.

In the case where one of In₂O₃ and SnO₂ is used as the host material,the content of the dopant material may be in a range of about 12 wt % toabout 15 wt %, and the content of the host material may be in a range ofabout 85 wt % to about 88 wt %.

In the case where a mixture of In₂O₃ and SnO₂ is used as the hostmaterial, the content of the dopant material may be in a range of about9 wt % to about 11 wt %, and the content of the host material may be ina range of about 89 wt % to about 91 wt %. In this case, the content ofSnO₂ in the host material may be preferably higher than that of In₂O₃,and for example, the content of SnO₂ may be in a range of about 50 wt %to about 70 wt %, and In₂O₃ may have a remaining content.

Here, as the content of the dopant material increases, the sheetresistance also increases. By adjusting the content of the dopantmaterial within the above range in consideration of this relationbetween the content and the sheet resistance, it may be possible tosecure the sheet resistance advantageous for the LCD device 10.

Meanwhile, the static electricity prevention layer 220 may be a layerthat is firstly deposited on the second substrate 102 and may bedeposited at a room or high temperature.

In the case where a mixture of In₂O₃ and SnO₂ is used as the hostmaterial, a content ratio of SnO₂ may be higher in the high temperaturedeposition than in the room temperature deposition. In other words, thecontent ratio of SnO₂ in the high temperature deposition may be higherthan the content ratio of SnO₂ in the room temperature deposition.

For example, when the deposition process is performed under a roomtemperature condition of about 15° C. to 100° C., the content of SnO₂may be in a range of 50 wt % to 60 wt %. By contrast, when thedeposition process is performed under a high temperature condition ofabout 100° C. to 300° C., the content of SnO₂ may be in a range of 60 wt% to 70 wt %.

Meanwhile, the sheet resistance may be changed depending on an amount ofoxygen (or an oxygen partial pressure) supplied into the sputteringdeposition chamber 400, and considering this, an oxygen amount may beadjusted in the sputtering process, which is performed on the staticelectricity prevention layer 220, so as to secure the sheet resistancerange required for the LCD device 10.

In detail, as an oxygen amount in a deposition process increases, asheet resistance of a deposition material decreases. That is, the sheetresistance may be in inverse proportion to the oxygen amount. Bycontrast, the sheet resistance may be in proportion to the content ofthe dopant material, as described above. Due to these relations, whenthe content of the dopant material is high, the required sheetresistance property can be achieved by increasing the oxygen amount, andwhen the content of the dopant material is low, the required sheetresistance property can be achieved by lowering the oxygen amount.

Here, the oxygen amount or the oxygen flow for securing the sheetresistance of the static electricity prevention layer 220 may be in arange of about 5 sccm to 20 sccm but is not limited to this range.

Next, referring to FIG. 6, the column spacer 160 may be formed on aninner surface of the second substrate 102, after the formation of thestatic electricity prevention layer 220. The column spacer 160 may beformed corresponding to non-display elements formed in the arraysubstrate (e.g., see AS of FIG. 4), and the non-display elements mayinclude the thin film transistor (e.g., T in FIG. 4), the data line(e.g., DL in FIG. 4), and the gate line (e.g., GL in FIG. 3).

The column spacer 160 may be formed by a mask process. For example, theformation of the column spacer 160 may include a process of depositingan organic material for the column spacer, a process of coating aphotoresist layer, a process of exposing the photoresist layer using aphotomask, a process of developing the exposed photoresist layer, anetching process of patterning the deposited organic material, and aprocess of stripping the photoresist layer. A thermal treatment processor a first thermal treatment process may be performed after the maskprocess.

Here, the thermal treatment process on the column spacer 160 may be aprocess of curing the organic material and may be performed at a hightemperature for a specific time (e.g., at about 230° C. for about 20minutes).

In an embodiment, the column spacer 160 may be formed to include a blackpigment (e.g., carbon), and in this case, the column spacer 160 may havea light-blocking function preventing or suppressing leakage light fromentering a neighboring pixel region, like the black matrix.

Next, referring to FIG. 7, the second alignment layer 192 may be formedby coating an alignment material on the inner surface of the secondsubstrate 102 provided with the column spacer 160, and then, a thermaltreatment process or a second thermal treatment process may be performedon the alignment material. For example, polyimide may be used as thematerial of the second alignment layer 192.

In an embodiment, a cleaning process may be performed on the secondsubstrate 102, before the coating of the alignment material.

Here, the thermal treatment process on the second alignment layer 192may be a process of curing the alignment material and may be performedat a high temperature for a specific time (e.g., at about 230° C. forabout 15 minutes).

As a result of the afore-described processes, the opposite substrate OSwith the static electricity prevention layer 220 may be fabricated.

In the afore-described process of fabricating the opposite substrate OS,the static electricity prevention layer 220 may be formed in advance ofthe processes of forming the column spacer 160 and the second alignmentlayer 192, and thus, the static electricity prevention layer 220 may beexposed to the subsequent processes. That is, the characteristics of thestatic electricity prevention layer 220 may be affected by thesubsequent processes.

For this reason, considering that the static electricity preventionlayer 220 is exposed to the subsequent process, the static electricityprevention layer 220 may be formed of the host and dopant materialswhose content ratios are in the afore-described proper ranges before theprocesses of forming the column spacer 160 and the second alignmentlayer 192. Accordingly, it may be possible to stably secure the propersheet resistance range of 10^(6.5) Ω/sq to 10⁹ Ω/sq and the propertransmittance of about 97% or higher, even when the static electricityprevention layer 220 is exposed to a process environment for subsequentprocesses (e.g., a developing solution (e.g., KOH) for forming thecolumn spacer 160, a thermal treatment process thereon, and a cleaningsolution (e.g., LGD-900) before the formation of the second alignmentlayer 192, and the thermal treatment process on the second alignmentlayer 192).

The liquid crystal panel (e.g., 100 in FIG. 4) may be fabricated bybonding the opposite substrate OS, which is fabricated by the aboveprocess, to the separately-fabricated array substrate (e.g., AS in FIG.4) with a liquid crystal layer (e.g., 105 in FIG. 4) interposedtherebetween.

The first and second polarizing plates (e.g., 201 and 202 in FIG. 4) maybe attached to the bottom and top surfaces of the liquid crystal panelfabricated by the above process, and then, the cover window (e.g., CW inFIG. 4) may be attached to a top surface of the second polarizing plate.Accordingly, the LCD device (e.g., 10 in FIG. 4) may be fabricated.

According to experiments to evaluate chemical resistance and reliabilitycharacteristics, for the LCD device according to the present embodiment,the static electricity prevention layer 220 had the sheet resistance andtransmittance characteristics that were maintained to the proper levels.These experiments will be described in more detail below. The followingtables comprise values of a sheet resistance of a plurality of samples.In the tables, the values of the sheet resistance are expressed as thelogarithm of the sheet resistance to base 10).

1. Comparative Experiment (Static Electricity Prevention Layer of GZTO)

In the comparative experiment, an in-cell touch LCD device had anon-inverted panel structure and included an opposite substrate, inwhich a static electricity prevention layer was made of GZTO, unlike thepresent disclosure. A substrate with the static electricity preventionlayer of GZTO was prepared as an experiment sample for the comparativeexperiment.

The results of the comparative experiment 1 were summarized in thefollowing Table 1 and FIG. 8.

TABLE 1 GZTO (O2 1.1%) GZTO (O2 4%) samples 1-1 1-2 1-3 2-1 2-2 2-3 Asdeposited 5.8 6 5.9 11.8 11.8 11.8 (after deposition) 230° C., 20 min8.1 7.9 7.8 7.4 8.5 8.4 230° C., 15 min 8.2 8 7.7 7.3 8.4 7.8  24 hr 6.16.2 6.1 5.9 6.3 6.1  48 hr 6 5.1 6.1 6 6.3 6.2 120 hr 6.3 6.4 6.3 6.26.5 6.4 144 hr 6.2 6.4 6.3 6.4 6.9 6.5 168 hr 5.8 5.9 5.9 5.6 5.9 5.8288 hr 5.6 5.9 5.5 5.2 5.4 5.4 336 hr 5.6 5.8 5.6 5.6 5.6 5.5 360 hr 5.55.7 5.6 5.6 5.7 5.6 384 hr 5.5 5.7 5.6 5.6 5.7 5.6 456 hr 5.5 5.6 5.65.5 5.7 5.6 480 hr 5.3 5.7 5.5 5.5 5.7 5.6 504 hr 5.3 5.6 5.5 5.5 5.75.7 528 hr 5.3 5.6 5.6 5.5 5.6 5.5 552 hr 5.3 5.6 5.5 5.5 5.6 5.5 624 hr5.5 5.6 5.5 5.6 5.6 5.5 648 hr 5.5 5.6 5.5 5.6 5.6 5.5 672 hr 5.3 5.75.5 5.6 5.9 5.6 696 hr 5.3 5.7 5.6 5.7 5.8 5.5 720 hr 5.6 5.8 5.6 5.85.8 5.7 792 hr 5.5 5.7 5.6 5.7 5.8 5.6 816 hr 5.5 5.8 5.6 5.6 5.8 5.6840 hr 5.5 5.8 5.7 5.7 5.8 5.6 864 hr 5.8 6.0 5.8 6.3 6.5 6.0 888 hr 5.06.5 5.3 6.5 6.8 6.3 960 hr 6.3 6.5 6.5 7.3 7.5 7.0 984 hr 6.3 6.5 6.57.0 7.3 7.0 1008 hr  6.3 6.5 6.5 7.0 7.0 6.9

In the comparative experiment, a 6090 reliability test (temperature of60° C. and humidity of 90%) was performed on three samples 1-1, 1-2, and1-3 (for an oxygen partial pressure of 1.1% in a test sputteringdeposition chamber) and on three samples 2-1, 2-2, and 2-3 (for anoxygen partial pressure of 4%). The sheet resistance characteristics ofthe samples were respectively measured after the sputtering depositionprocess, after two thermal treatment processes, and when elapsed timeunder condition for the 6090 reliability test reached some preset times.

In Table 1, the expression “230° C., 20 min” represents a processcondition of a thermal treatment process performed on the column spacer,and the expression “230° C., 15 min” represents a process condition of athermal treatment process performed on the second alignment layer.

In FIG. 8, the y-axis represents an exponent of a sheet resistancewritten with a base of 10 (i.e., logarithm of sheet resistance to base10).

Referring to Table 1 and FIG. 8, the sheet resistance in the comparativeexperiment decreased by about 10^(1.5)-10² Ω/sq, after 24 hr from thefinish time of the two thermal treatment processes, decreased by about10^(1.8)-10^(2.8) Ω/sq after 300 hr to show a saturated behavior, butreversely increased after 800 hr.

This result shows that the static electricity prevention layer of GTZOin the comparative experiment does not have good film quality, has anunstable sheet resistance characteristic, and could not secure theproper sheet resistance of 10^(6.5) to 10⁹ Ω/sq.

This means that the static electricity prevention layer made of GTZOcould not be applied to a touch LCD device.

2. The Experiment 1 of the Present Disclosure (Static ElectricityPrevention Layer, in which Nb₂O₅, and SnO₂ were Respectively Used asDopant and Host)

In the experiment 1 of the present disclosure, an in-cell touch LCDdevice had a non-inverted panel structure and included an oppositesubstrate and a static electricity prevention layer on an outer surfaceof the opposite substrate, where the static electricity prevention layerwas formed using Nb₂O₅ and SnO₂ as dopant and host materials,respectively. A substrate with the static electricity prevention layerof Nb₂O₅ and SnO₂ was prepared as an experiment sample for theexperiment 1 of the present disclosure.

The results of the experiment 1 were summarized in the following Table 2and FIGS. 9 and 10 visually illustrating the data of Table 2.

TABLE 2 10TNO 11TNO 12.5TNO O2 pressure 5% 6% 7% 5% 5% 7% 5% 6% 7% afterthermal 6.00 5.60 5.48 6.30 5.85 5.60 7.00 6.48 6.60 treatment  24 h5.70 5.30 5.30 6.00 5.60 5.48 6.70 6.30 6.30  48 h 5.70 5.30 5.30 6.005.70 5.48 6.70 6.30 6.30 120 h 5.70 5.48 5.48 6.00 5.70 5.48 6.78 6.306.30 144 h 5.78 5.30 5.30 6.00 5.60 5.48 6.60 6.00 6.30 168 h 5.85 5.305.48 6.00 5.70 5.60 6.70 6.30 6.30 192 h 5.85 5.30 5.30 6.00 5.60 5.486.60 6.00 6.00 216 h 5.78 5.30 5.00 5.85 5.60 5.48 6.60 6.00 6.00 288 h6.00 5.30 5.30 6.00 5.78 5.48 6.78 6.30 6.30 312 h 5.78 5.30 5.30 6.005.70 5.48 6.78 6.30 6.30 336 h 5.78 5.30 5.30 5.95 5.60 5.30 6.70 6.006.30 360 h 5.78 5.30 5.30 5.95 5.60 5.48 6.78 6.30 6.30 384 h 5.78 5.305.30 6.00 5.70 5.48 6.70 6.30 6.30 456 h 5.90 5.30 5.30 6.00 5.78 5.606.78 6.30 6.48 480 h 5.78 5.30 5.30 6.00 5.70 5.48 6.85 6.48 6.48 504 hr5.90 5.30 5.30 6.00 5.70 5.48 6.95 6.48 6.60 528 hr 5.90 5.30 5.48 6.305.85 5.60 6.85 6.48 6.48 552 hr 5.90 5.30 5.48 6.30 5.78 5.60 6.85 6.486.48 624 hr 6.00 5.30 5.60 6.30 5.85 5.70 7.00 6.60 6.70 648 hr 5.955.30 5.48 6.30 5.78 5.70 6.85 6.48 6.60 672 hr 6.00 5.48 5.60 6.30 5.905.78 6.85 6.60 6.70 696 hr 6.00 5.60 5.60 6.48 6.00 5.90 6.90 6.70 6.78720 hr 6.00 5.48 5.48 6.30 6.00 5.78 6.85 6.60 6.60 792 hr 6.00 5.305.30 6.00 6.00 5.60 6.78 6.30 6.30 840 hr 6.00 5.48 5.60 6.30 6.00 5.856.95 6.60 6.60 864 hr 5.95 5.30 5.30 6.00 5.78 5.60 6.70 6.30 6.30 888hr 6.00 5.48 5.48 6.30 6.00 5.85 6.85 6.60 6.60 1008 hr  6.00 5.60 5.486.30 6.00 5.85 6.85 6.60 6.48 1032 hr  6.00 5.48 5.48 6.30 6.00 5.856.85 6.60 6.60

In the experiment 1, the 6090 reliability test was performed on sampleshaving dopant content ratios of 10 wt %, 11 wt %, and 12.5 wt %, and thetest for each sample was performed under oxygen partial pressureconditions of 5%, 6%, and 7% in a test sputtering deposition chamber.The sheet resistances of the samples were measured when the sputteringdeposition process was finished, when two thermal treatment processeswere finished, and when elapsed time under condition for the 6090reliability test reached some preset times.

Meanwhile, in the experiment 1, the static electricity prevention layerwas formed by a deposition process at a room temperature (50° C.).

FIG. 9 shows sheet resistances of the samples (for the oxygen partialpressure of 5% and the dopant content ratios of 10 wt %, 11 wt %, and12.5 wt %), and FIG. 10 shows sheet resistances of the samples (for thedopant content ratio of 12.5 wt % and the oxygen partial pressures of5%, 6%, and 7%).

Referring to Table 2 and FIGS. 9 and 10, in the experiment 1, when thesample had the dopant content ratio of 12.5 wt %, the sheet resistancewas in the proper range of 10^(6.5)-10⁹ Ω/sq, whereas when the samplehad the dopant content ratios of 10 wt % and 11 wt %, the sheetresistance was not in the proper range.

The transmittances measured in the present experiment 1 and the sheetresistances measured in the chemical resistance evaluation arerespectively summarized in the following Tables 3 and 4 and FIGS. 11 and12 visually illustrating the data of Tables 3 and 4.

TABLE 3 10TNO (Nb₂O₅ 10%) 11TNO (Nb₂O₅ 11%) 12.5TNO (Nb₂O₅ 12.5%) O₂pressure 5% 6% 7% 5% 6% 7% 5% 6% 7% Avg 97.94 98.09 98.47 98.03 98.3798.30 98.07 98.29 97.59 (380 nm~760 nm) at 550 nm 97.92 98.16 98.5798.26 98.53 98.55 98.41 98.42 97.80

TABLE 4 12.5TNO_5% 12.5TNO_6% 12.5TNO_7% As deposited 7.60 7.30 7.00(after deposition) 230° C., 20 min 7.60 7.30 7.00 KOH 6 min 7.85 — 7.48LGD-900 6 min 7.48 7.00 —

Table 3 and FIG. 11 show results of transmittance versus wavelength,obtained from the samples whose dopant content ratios were 10 wt %, 11wt %, and 12.5 wt % when the oxygen partial pressures were 5%, 6%, and7%.

Table 4 and FIG. 12 show sheet resistances measured from the chemicalresistance test on the samples whose dopant content ratio was 12.5 wt %when the oxygen partial pressures were 5%, 6%, and 7%. In Table 4 andFIG. 12, the sheet resistances of the static electricity preventionlayer were measured after the deposition process, after a thermaltreatment process under a thermal treatment condition (“230° C., 20min”) for the column spacer, after a developing solution treatmentprocess under a developing solution treatment condition (“KOH (0.04%), 6min”) for the column spacer, and after a cleaning solution treatmentprocess under a cleaning solution treatment condition (“LGD-900, 6 min”)before coating an alignment layer. The developing and cleaning solutiontreatment processes correspond to the chemical resistance test, and theconditions for the developing and cleaning solution treatment processeswere set to be harsher than the real conditions for relevant processes.

Table 3 and FIG. 11 show that, for the samples, it is possible to securethe proper transmittance of 97% or higher within a visible wavelengthrange (e.g., from 380 to 760 nm).

Table 4 and FIG. 12 show that the sheet resistances measured in thechemical resistance test were within the proper sheet resistance range.This means that the samples could have the desired chemical resistantproperty.

3. The Experiment 2 of the Present Disclosure (Static ElectricityPrevention Layer, in which SiO₂ and In₂O₃+SnO₂ were Used as Dopant andHost, and which was Deposited at Room Temperature)

In the experiment 2 of the present disclosure, an in-cell touch LCDdevice had a non-inverted panel structure and included an oppositesubstrate and a static electricity prevention layer on an outer surfaceof the opposite substrate, where the static electricity prevention layerwas formed by a deposition process, in which SiO₂ and In₂O₃+SnO₂ wererespectively used as the dopant and host materials, and which wasperformed at a room temperature (50° C.). A substrate with the staticelectricity prevention layer of SiO₂ and In₂O₃+SnO₂ was prepared as anexperiment sample for the experiment 2 of the present disclosure.

The results of the experiment 2 were summarized in the following Table 5and FIGS. 13 to 15 visually illustrating the data of Table 5.

TABLE 5 40SITO 50SITO 60SITO O2 pressure 5% 6% 7% 5% 6% 7% 5% 6% 7% Asdeposited 8.00 8.48 10.00 7.70 7.78 8.30 8.00 8.48 9.30 (afterdeposition) KOH 8.78 9.78 10.70 8.00 8.30 9.30 8.48 8.85 9.85 (25° C.,210 sec) 230° C. 20 min 9.00 9.48 9.95 7.90 7.60 7.30 8.48 7.70 7.60230° C. 15 min 9.30 9.00 9.48 8.30 7.48 7.48 8.85 8.48 8.00 0 9.30 9.009.48 8.30 7.48 7.48 8.85 8.48 8.00 24 8.30 8.60 8.95 7.30 6.90 6.70 7.607.78 7.30 48 8.90 9.48 10.00 7.48 6.95 7.48 8.00 8.30 8.00 216 8.78 8.709.00 7.00 7.00 7.30 7.60 7.70 7.48 288 8.85 7.78 9.30 7.30 7.30 7.307.78 7.85 7.78 312 8.70 8.90 9.30 7.30 7.48 7.48 7.78 7.85 7.85 336 8.788.95 9.30 7.30 7.30 7.60 7.78 7.35 7.78 360 8.85 9.00 9.30 7.30 7.487.60 7.85 8.00 8.00 384 8.30 8.95 9.30 7.00 7.30 7.30 7.70 7.70 7.70 4568.78 9.00 9.30 7.30 7.48 7.60 7.85 7.90 7.85 504 8.95 9.30 9.48 7.307.60 7.70 7.90 8.00 7.95 528 8.60 8.90 9.00 7.00 7.48 7.30 7.70 7.607.70 552 9.30 9.48 9.70 7.48 7.85 7.95 8.30 8.30 8.48 624 8.48 9.30 9.007.00 7.00 7.30 7.48 7.60 7.60 648 8.78 8.90 9.00 7.30 7.48 7.60 7.907.90 7.85 696 8.30 8.48 8.85 6.90 7.00 7.30 7.48 7.48 7.60 792 8.70 9.009.00 7.30 7.30 7.70 7.95 7.90 7.90 840 8.48 8.70 8.85 7.00 7.30 7.307.60 7.60 7.60 888 8.60 8.90 9.00 7.30 7.48 7.48 7.78 7.85 7.78 960 9.009.30 9.60 7.00 7.48 7.48 8.00 8.30 8.00 1008 8.60 8.78 9.00 7.00 7.487.70 7.70 7.78 7.78 1056 8.70 8.95 9.30 7.30 7.00 7.70 7.78 7.95 7.85

In the experiment 2, the 6090 reliability test was performed on samples,in which dopant content ratios were 9 wt % and SnO₂ content ratios inthe host were 40 wt %, 50 wt %, and 60 wt %, and the test for eachsample was performed under oxygen partial pressure conditions of 5%, 6%,and 7% in a test sputtering deposition chamber. The sheet resistances ofthe samples were measured after the sputtering deposition process, afterthe developing solution treatment process, after two thermal treatmentprocesses, and when elapsed time under condition for the 6090reliability test reached some preset times.

Each of FIGS. 13, 14, and 15 shows sheet resistances of the samples,whose SnO₂ content ratios in the host were 40 wt %, 50 wt %, and 60 wt%.

Referring to Table 5 and FIGS. 13 to 15, in the experiment 2, when thesample had the SnO₂ content ratios of 50 wt % and 60 wt %, the sheetresistances were within the proper sheet resistance range of 10^(6.5) to10⁹ Ω/sq, whereas when the sample had the content ratio of 40 wt %, thesheet resistance was not in the proper sheet resistance range.

The following Table 6 shows transmittances of the samples in the presentexperiment 2, measured from the chemical resistance test and thereliability test.

TABLE 6 40SITO (SnO2 40%) 50SITO (SnO2 50%) 60SITO (SnO2 60%) O₂pressure 5% 6% 7% 5% 6% 7% 5% 6% 7% As deposited 97.88 98.19 98.26 96.9697.55 97.77 96.79 97.48 97.41 (after deposition) chemical 97.76 98.0298.14 97.22 97.06 97.57 97.22 97.06 97.57 resistance test reliabilitytest 97.92 98.37 98.40 97.34 97.20 97.84 97.50 97.07 97.87

Table 6 shows transmittances of samples having SnO₂ content ratios of 40wt %, 50 wt %, and 60 wt %, respectively, measured in the chemicalresistance test and the reliability test.

Referring to Table 6, in the chemical resistance test and thereliability test, the samples had transmittances of 97% or higher, whichwere in the proper transmittance range. This means that the samples inthe present experiment 2 could have sufficient chemical resistance andreliability.

4. The Experiment 3 of the Present Disclosure (Static ElectricityPrevention Layer, in Which SiO₂ and In₂O₃+SnO₂ Were Used as Dopant andHost, Which was Deposited at High Temperature)

In the experiment 3 of the present disclosure, an in-cell touch LCDdevice had a non-inverted panel structure and included an oppositesubstrate and a static electricity prevention layer on an outer surfaceof the opposite substrate, where the static electricity prevention layerwas formed by a deposition process, in which SiO₂ and In₂O₃+SnO₂ wererespectively used as the dopant and host materials, and which wasperformed at a high temperature (200° C.). A substrate with the staticelectricity prevention layer of SiO₂ and In₂O₃+SnO₂ was prepared as anexperiment sample for the experiment 3 of the present disclosure.

The results of the experiment 3 are summarized in FIGS. 16A-16F andFIGS. 17A-17F.

In the experiment 3, the thermal treatment stability test, the chemicalresistance test, and the 6090 reliability test were performed onsamples, in which dopant content ratios were 9 wt %, 10 wt %, and 11 wt% and SnO₂ content ratios in the host were 60 wt %, when the oxygenpartial pressures in a test sputtering deposition chamber were 3%, 4%,5%, 6%, and 7%.

In FIG. 16, the results of the thermal treatment stability test areshown in FIGS. 16A, 16B, and 16C, and the combined results of thethermal treatment stability and chemical resistance tests are shown inFIGS. 16D, 16E, and 16F. Here, the results of the thermal treatmentstability test were sheet resistances measured after two thermaltreatment processes (230° C., 20 min; 230° C., 15 min), and the combinedresults of the thermal treatment stability and chemical resistance testswere sheet resistances measured after two thermal treatment processesand two chemical resistance treatment processes (KOH, 90 seconds;LGD-900, 70 seconds).

In FIG. 17, the results of the 6090 reliability test are shown in FIGS.17A, 17B, and 17C, and the combined results of the 6090 reliability andchemical resistance tests are shown in FIGS. 17D, 17E, and 17F. Here,the results of the 6090 reliability test were sheet resistances measuredafter the 6090 reliability test, and the combined result of the 6090reliability and chemical resistance tests were sheet resistancesmeasured after the 6090 reliability and chemical resistance treatments.

Referring to FIGS. 16A-16F and FIGS. 17A-17F, the results obtained inthe experiment 3 show that, when the SnO₂ content ratios were 60 wt %and the dopant content ratios were 9 wt %, 10 wt %, and 11 wt %, it ispossible to secure the proper sheet resistance of 10^(6.5) to 10⁹ Ω/sqby adjusting the oxygen partial pressure. In detail, as the contentratio of SiO₂ increases, the sheet resistance increases, and even insuch cases, by increasing the oxygen partial pressure, it may bepossible to secure the proper sheet resistance, when the content ratioof SiO₂ increases.

The chemical resistance treatment led to a very small change in sheetresistance, and this means that the sheet resistance property before thechemical resistance treatment was substantially equivalent to that afterthe chemical resistance treatment.

The following Tables 7 and 8 show transmittances of the samples in thepresent experiment 3, measured from the reliability test and thechemical resistance test.

TABLE 7 60SITO O₂ pressure 3% 4% 5% 6% 7% Avg(380~760 nm) 97.50 97.6697.43 98.09 98.28 at 550 nm 98.17 98.25 97.92 98.48 98.67

TABLE 8 60SITO O₂ pressure 3% 4% 5% 6% 7% Avg(380~760 nm) 97.25 97.4397.87 98.05 98.09 at 550 nm 97.82 97.89 98.21 98.38 98.31

Table 7 and Table 8 show transmittances of samples having a SnO₂ contentratio of 60 wt %, measured in the reliability test and the chemicalresistance test, respectively.

Referring to these results, the samples had transmittances of 97% orhigher, which were in the proper transmittance range, and this meansthat the samples in the present experiment 3 could have sufficientreliability and chemical resistance.

The results of the experiments show that it is possible to secure theproper sheet resistance range and the proper transmittance range for thestatic electricity prevention layer, which is formed on the outersurface of the opposite substrate according to an embodiment of thepresent invention. Meanwhile, in the experiments, the process conditionassociated with the oxygen amount in the deposition process of thestatic electricity prevention layer was represented in terms of theoxygen partial pressure, for convenience's sake, but this condition maybe represented in terms of an amount of oxygen. For example, the oxygenflow for the proper sheet resistance and transmittance ranges may be ina range of about 5 sccm to 20 sccm.

As described above, in the touch LCD device of the in-cell structureaccording to an embodiment of the present disclosure, the staticelectricity prevention layer, which is formed of a host materialincluding at least one of In₂O₃ and SnO₂ and a dopant material includingat least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅, may be formed on theouter surface of the opposite substrate.

Accordingly, it may be possible to effectively secure a sheet resistanceof about 10^(6.5) Ω/sq to about 10⁹ Ω/sq, which is required to preventthe issues of static electricity and interference with touch-inducedcapacitance, and to effectively secure a transmittance of about 97% orhigher, which is required to maintain the image brightness to a desiredlevel.

Thus, the opposite substrate can be disposed adjacent to the displaysurface or the top surface of the liquid crystal panel 100, and thus,the in-cell touch LCD device can be configured to have the non-invertedpanel structure.

As a result, it is possible to effectively overcome the problems in theconventional inverted panel structure. For example, it is unnecessary toform an additional inorganic insulating layer for reducing therecognition of reflection by the gate metal in the inverted panelstructure. Furthermore, it is unnecessary to provide an expensivepolarizing plate having a static electricity prevention function nearthe display surface, and a typical polarizing plate can becost-effectively used in the inverted panel structure. In addition, anadditional apparatus for inverting the panel is not required.

Furthermore, the static electricity prevention layer may be formed usingthe existing sputtering system, which is used to form a transparentconductive layer on the outer surface of the opposite substrate, as itis, and thus, there is no additional cost to prepare a new system.

Thus, it may be possible to improve productivity and to reducefabrication cost.

In the touch LCD device of the in-cell structure according to thepresent disclosure, the static electricity prevention layer, which isformed of a host material including at least one of In₂O₃ and SnO₂ and adopant material including at least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, andTa₂O₅, may be formed on the outer surface of the opposite substrate.

Accordingly, it may be possible to effectively secure a sheet resistanceof about 10^(6.5) Ω/sq to about 10⁹ Ω/sq, which is required to preventthe issues of static electricity and interference with touch-inducedcapacitance, and to effectively secure a transmittance of about 97% orhigher, which is required to maintain the image brightness to a desiredlevel.

Thus, the opposite substrate can be disposed adjacent to the displaysurface or the top surface of the liquid crystal panel 100, and thus,the in-cell touch LCD device can be configured to have the non-invertedpanel structure.

As a result, it is possible to effectively overcome the problems in theconventional inverted panel structure. For example, it is unnecessary toform an additional inorganic insulating layer for reducing therecognition of reflection by the gate metal in the inverted panelstructure. Furthermore, it is unnecessary to provide an expensivepolarizing plate having a static electricity prevention function nearthe display surface, and a typical polarizing plate can becost-effectively used in the inverted panel structure. In addition, anadditional apparatus for inverting the panel is not required.

Furthermore, the static electricity prevention layer may be formed usingthe existing sputtering system, which is used to form a transparentconductive layer on the outer surface of the opposite substrate, as itis, and thus, there is no additional cost to prepare a new system.

Thus, it may be possible to improve productivity and to reducefabrication cost.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in a display device of thepresent disclosure without departing from the sprit or scope of thedisclosure. Thus, it is intended that the present disclosure covers themodifications and variations of this disclosure provided they comewithin the scope of the appended claims and their equivalents.

What is claimed is:
 1. A liquid crystal display device, comprising: anarray substrate including a first substrate, which is placed adjacent toa backlight, and a thin film transistor and a touch electrode which areprovided on the first substrate; and an opposite substrate including asecond substrate, which faces the first substrate with a liquid crystallayer interposed therebetween, and a static electricity prevention layerwhich is deposited on an outer surface of the second substrate, whereinthe static electricity prevention layer is formed of a host materialcontaining at least one of In₂O₃ and SnO₂ and a dopant materialcontaining at least one of ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅ or formed of ahost material containing In₂O₃ and SnO₂ and a dopant material containingSiO₂ and has sheet resistance of 10^(6.5) Ω/sq to 10⁹ Ω/sq, and whereinthe array substrate further includes a touch line connected to the touchelectrode and a data line connected to the thin film transistor andextending in a first direction, and the touch line has a narrower widththan the touch electrode along a second direction perpendicular to thefirst direction and is disposed between the touch electrode and the dataline.
 2. The liquid crystal display device of claim 1, wherein a contentratio of the dopant material is in a range of 9 wt % to 15 wt %, and acontent ratio of the host material is in a range of 85 wt % to 91 wt %.3. The liquid crystal display device of claim 2, wherein, when the hostmaterial is one of In₂O₃ and SnO₂, the content ratio of the dopantmaterial is in a range of 12 wt % to 15 wt % and the content ratio ofthe host material is in a range of 85 wt % to 88 wt %, and when the hostmaterial is In₂O₃ and SnO₂, the content ratio of the dopant material isin a range of 9 wt % to 11 wt % and the content ratio of the hostmaterial is in a range of 89 wt % to 91 wt %.
 4. The liquid crystaldisplay device of claim 3, wherein, when the host material is In₂O₃ andSnO₂, the content ratio of the SnO₂ is in a range of 50 wt % to 70 wt %.5. The liquid crystal display device of claim 1, wherein a thickness ofthe static electricity prevention layer is in a range of 100 Å to 300 Å.6. The liquid crystal display device of claim 1, wherein the staticelectricity prevention layer has a transmittance of 97% or higher. 7.The liquid crystal display device of claim 1, wherein the oppositesubstrate comprises: a column spacer on an inner surface of the secondsubstrate; and an alignment layer on the column spacer and the innersurface of the second substrate.
 8. The liquid crystal display device ofclaim 7, wherein the column spacer overlaps the touch line and the dataline.
 9. The liquid crystal display device of claim 1, furthercomprising: a polarizing plate attached to a top surface of the staticelectricity prevention layer; and a cover window attached to a topsurface of the polarizing plate.
 10. The liquid crystal display deviceof claim 1, wherein the array substrate comprises a pixel electrode anda color filter pattern formed in a pixel region, and the color filterpattern is disposed between the touch line and the data line, andwherein an electric field driving the liquid crystal layer is producedbetween the pixel electrode and the touch electrode, during an imagedisplay period.
 11. The liquid crystal display device of claim 1,wherein, when the host material is In₂O₃ and SnO₂ and the dopantmaterial is SiO₂, a content ratio of the In₂O₃ is higher than a contentratio of the SiO₂ and is lower than a content ratio of the SnO₂.
 12. Amethod of fabricating a liquid crystal display device, comprising:fabricating an array substrate including a first substrate, which isplaced adjacent to a backlight, and a thin film transistor and a touchelectrode which are provided on the first substrate; and fabricating anopposite substrate including a second substrate, which faces the firstsubstrate with a liquid crystal layer interposed therebetween, and astatic electricity prevention layer which is deposited on an outersurface of the second substrate, wherein the static electricityprevention layer is formed of a host material containing at least one ofIn₂O₃ and SnO₂ and a dopant material containing at least one of ZrO₂,HfO₂, Nb₂O₅, and Ta₂O₅ or formed of a host material containing In₂O₃ andSnO₂ and a dopant material containing SiO₂ and has sheet resistance of10^(6.5) Ω/sq to 10⁹ Ω/sq, and wherein the array substrate furtherincludes a touch line connected to the touch electrode and a data lineconnected to the thin film transistor and extending in a firstdirection, and the touch line has a narrower width than the touchelectrode along a second direction perpendicular to the first directionand is disposed between the touch electrode and the data line.
 13. Themethod of claim 12, wherein a content ratio of the dopant material is ina range of 9 wt % to 15 wt %, and a content ratio of the host materialis in a range of 85 wt % to 91 wt %.
 14. The method of claim 13,wherein, when the host material is one of In₂O₃ and SnO₂, the contentratio of the dopant material is in a range of 12 wt % to 15 wt % and thecontent ratio of the host material is in a range of 85 wt % to 88 wt %,and when the host material is In₂O₃ and SnO₂, the content ratio of thedopant material is in a range of 9 wt % to 11 wt % and the content ratioof the host material is in a range of 89 wt % to 91 wt %.
 15. The methodof claim 14, wherein, when the host material is In₂O₃ and SnO₂, thecontent ratio of the SnO₂ is in a range of 50 wt % to 70 wt %.
 16. Themethod of claim 15, wherein, when the static electricity preventionlayer is deposited at a temperature lower than 100° C., the contentratio of SnO₂ is in a range of 50 wt % to 60 wt %, when the staticelectricity prevention layer is deposited at a temperature of 100° C. orhigher, the content ratio of SnO₂ is in a range of 60 wt % to 70 wt %.17. The method of claim 12, wherein a thickness of the staticelectricity prevention layer is in a range of 100 Å to 300 Å.
 18. Themethod of claim 12, wherein the static electricity prevention layer hasa transmittance of 97% or higher.
 19. The method of claim 12, furthercomprising: attaching a polarizing plate to a top surface of the staticelectricity prevention layer; and attaching a cover window to a topsurface of the polarizing plate.
 20. The method of claim 12, wherein thearray substrate comprises a pixel electrode and a color filter patternformed in a pixel region, the color filter pattern is disposed betweenthe touch line and the data line, and an electric field driving theliquid crystal layer is produced between the pixel electrode and thetouch electrode, during an image display period.
 21. A method offabricating a liquid crystal display device, comprising: fabricating anarray substrate including a first substrate, which is placed adjacent toa backlight, and a thin film transistor and a touch electrode which areprovided on the first substrate; and fabricating an opposite substrateincluding a second substrate, which faces the first substrate with aliquid crystal layer interposed therebetween, and a static electricityprevention layer which is deposited on an outer surface of the secondsubstrate, wherein the static electricity prevention layer is formed ofa host material containing at least one of In₂O₃ and SnO₂ and a dopantmaterial containing at least one of SiO₂, ZrO₂, HfO₂, Nb₂O₅, and Ta₂O₅and has sheet resistance of 10^(6.5) Ω/sq to 10⁹ Ω/sq, and wherein thefabricating of the opposite substrate comprises: depositing the staticelectricity prevention layer on the outer surface of the secondsubstrate using a sputtering method; performing a mask process includinga developing process to form a column spacer on an inner surface of thesecond substrate on which the static electricity prevention layer isdeposited, and then performing a first thermal treatment process;performing a cleaning process after the first thermal treatment process;coating an alignment layer after the cleaning process, and thenperforming a second thermal treatment process.
 22. The method of claim21, wherein an oxygen flow in a deposition chamber is in a range of 5sccm to 20 sccm, when the static electricity prevention layer isdeposited.
 23. The method of claim 22, wherein the sheet resistance ofthe static electricity prevention layer is in inverse proportion to theoxygen flow in the deposition chamber.